Turf mowers having one or more reel cutting units carried on a frame for cutting grass over a wide cutting swath are well known. In a gang mower configuration, a plurality of reel cutting units are usually arranged in front and rear rows with the cutting units in each row being laterally spaced from one another if there is more than one cutting unit in each row. The cutting units in the respective rows are laterally staggered relative to the cutting units in the other rows so that the gaps between the cutting units in one row are covered by the cutting unit(s) in another row. This allows the gang configuration of cutting units to cut an unbroken swath of grass during a single pass of the gang mower. Typically, gang mowers of this type comprise riding mowers that are operated by an operator carried on a seat provided on the mower.
Turf mowers of this type traditionally have been powered by an internal combustion engine carried on the frame of the mower, typically either a diesel engine or a gasoline powered engine. In many cases, the engine powers one or more hydraulic pumps that supply pressurized hydraulic fluid to a plurality of hydraulic motors that power the reel cutting units. The reel cutting units are available in different diameters, e.g. cutting units having a 5 inch diameter reel or cutting units having a 7 inch diameter reel. The reason for this is that different diameter reels are more effective in cutting different types of grass or at different times of the year. However, because of substantially different hydraulic requirements depending upon whether 5 inch or 7 inch reel cutting units are used, the traction unit that carry such cutting units had to be individually designed and manufactured for each sized reel cutting units. The same traction unit having the same hydraulic system could not be used to power both 5 inch reel cutting units and 7 inch cutting units, without significant changes to the hydraulic system.
The result of this fact meant that a manufacturer had to manufacture one traction unit to carry 5 inch hydraulic reel cutting units and a second separate traction unit to carry 7 inch hydraulic reel cutting units. A customer who wished to have both sizes of reel cutting units available for use had to purchase two different traction units each equipped with the size of reel cutting unit for which they were designed. Needless to say, this was expensive for the customer. It was also expensive for the manufacturer since a common traction unit platform could not be manufactured to carry both sizes of reel cutting units.